Properties Of Solids And Liquids Question 59
Question: A block of mass 100 gm slides on a rough horizontal surface. If the speed of the block decreases from 10 m/s to 5 m/s, the thermal energy developed in the process is [UPSEAT 2002]
Options:
A) 3.75 J
B) 37.5 J
C) 0.375 J
D) 0.75 J
Show Answer
Answer:
Correct Answer: A
Solution:
According to energy conservation, change in kinetic energy appears in the form of heat (thermal energy). therefore i.e. Thermal energy $ =\frac{1}{2}m(v _{1}^{2}-v _{2}^{2}) $
$ [ \because \underset{\text{(Joule)}}{\mathop{W}}=\underset{\text{(Joule)}}{\mathop{Q}} ] $
$ =\frac{1}{2}(100\times {{10}^{-3}})(10^{2}-5^{2})=3.75J $
